This application relates to a hose-end sprayer of the type set forth in U.S. Pat. No. 6,378,785, commonly owned herewith. This invention is an improvement over the venting feature disclosed in that patent, and the entirety of the disclosure of U.S. Pat. No. 6,378,785 is specifically incorporated herein by reference.
A hose-end sprayer is disclosed in U.S. Pat. No. 6,578,776 which includes a venting feature as required to replenish aspirated product from the container with air to avoid container collapse and any malfunctioning of the system. The sprayer has a cylindrical control valve 20 positioned in a cylindrical transverse bore 22 for rotation between ON and OFF positions. Valve 20 includes a sealing portion 63 that forms an annular seal with bore 22 around the interface between chemical passage 32 and a first passage 56 formed in the valve. The sprayer head assembly includes a vent passage 52 defined by a small hole formed in head 14 of the assembly. The vent passage communicates with the interior of the container and with the interior of cylindrical bore 22. Sealing member 64 on the valve includes a vent channel 68 which, in the valve open position, is aligned with vent passage 52. Accordingly, channel 68 allows passage 52 to communicate with gaps that are formed between valve 20 and its bore 22 such that in the valve open position vent passage 52 communicates with atmosphere. In the closed position of the valve, a portion of sealing member 64 overlies vent port 52 to interrupt communication with its vent channel 68 to thereby close the vent in the valve closed position. When valve 20 is rotated into its closed position, carrier passage 46, chemical passage 32, and vent passage 52 are all closed by the valve.
The sprayer head assembly of the U.S. Pat. No. 6,578,776 patent thus includes a valve chamber in communication with chemical and carrier liquid passages, with the valve movably positioned within the valve chamber. The vent passage is in communication with the valve chamber so as to likewise communicate with the carrier passage, in the valve open positions, via the gap between valve 20 and its transverse bore 22.
The drawback with such a venting system for this type of sprayer is the tendency during the vent/valve open position for liquid from the carrier passage to enter the container through the gap between 20 and 22, through vent channel 68 and through vent passage 52. This unwanted liquid, i.e., water, dilutes the chemical product in the container during repeated usage of the sprayer thus reducing the effectiveness of the chemical.